Approximately 8 per 1,000 people in the U.S. (>2.4 million) require augmentative and alternative communication (AAC), and surprisingly high percentage - about 24% - of preschool speech-language pathologists'(SLPs) caseloads consists of children who need AAC. Many children using AAC have receptive language profiles indicating the potential to use generative language. However, even when children who use AAC possess relatively strong receptive language profiles, they frequently have poor expressive language outcomes. The long-term aim of this line of research is to identify intervention approaches that ameliorate the expressive language deficits of children who use AAC, a goal well-suited to the NIDCD's mission to address biomedical and behavioral problems associated with individuals who have communication disorders. The proposed project is comprised of two specific aims: Aim 1 is to evaluate the effect of an aided AAC modeling with contrastive targets intervention on the productive use of two-term semantic- syntactic relations (e.g., action-object) by preschoolers who use AAC, and Aim 2 focuses on evaluating the participants'ability to generalize learning to untrained semantic-syntactic relations. Children with relatively strong pre-treatment comprehension levels (i.e., >1.5 SD of the mean on the TACL-3) will be included in the study. It is predicted that all children will make at least some gains with producing syntactically correct messages. An experimentally controlled single subject, multiple probes across targets and participants design will be used to evaluate outcomes, and a Simulated Modeling Analysis will be used to measure the statistical significance of each participant's progress. A total of 16 children who use AAC (ages 4-5) will participate. Each child will be instructed in the use of three semantic-syntactic relations with three additional generalization measures. The aided AAC modeling with contrastive targets intervention will include models of reversible targets (e.g., DOG BITES PIG;PIG BITES DOG) provided on the child's AAC device. Innovations for the proposed AAC study include: (1) teaching children to 'map'spoken language onto AAC devices;(2) teaching syntactic rules, an area largely ignored with AAC populations;and (3) emphasizing word order, which is particularly problematic for children using AAC. The outcomes of this project will have immediate implications for intervention and will serve as the basis for larger and more refined (R01) intervention studies. PUBLIC HEALTH RELEVANCE: The proposed research is relevant to public health because it aims to contribute to a program of research focused on significantly improving the clinical services offered to children who use augmentative and alternative communication (AAC). Because the project is focused on ameliorating the long-term expressive language deficits of children who use AAC, the project is relevant to NIDCD's mission to address the biomedical and behavioral problems associated with individuals who have communication disorders. Failing to attain functional language skills presents a significant public health problem;these outcomes have profound effects on short- and long-term educational and social outcomes, as well having lifelong negative impacts on employment opportunities.